ValueError: Unknown format code 'x' for object of type 'str'

[Bouke]

Running this on macOS 10.15 with python 3.8, I'm running into the following issue:

Traceback (most recent call last):
  File "ap2-receiver.py", line 1108, in <module>
    print(f'Enabled features: {FEATURES:016x}')
  File "/usr/local/Cellar/python@3.8/3.8.6/Frameworks/Python.framework/Versions/3.8/lib/python3.8/enum.py", line 669, in __format__
    return cls.__format__(val, format_spec)
ValueError: Unknown format code 'x' for object of type 'str'

After removing the format specifier the server boots up and starts listening.

[systemcrash]

What did you provide as a command line?